How can I catch a rendering error / missing template in node.js using express.js?

Question

I have code like this that will render a jade template without a route defined. Think of this like the express.static but it calls res.render with the url.

app.use(function (req, res, next) {     try {         res.render(req.url.substring(1), { title: "No Controller", user: req.session.user });     } catch (err) {         console.log(err)         next();     } }); 

The problem is that res.render() isn't throwing an error. Instead it is rendering an error page. Is there a way to detect a missing template or any rendering errors?

Answer 1

A better way to do it, instead of requiring fs and having another callback, would be to use render's callback :

res.render(my_page_im_not_sure_it_exists, {}, function(err, html) {     if(err) {         res.redirect('/404'); // File doesn't exist     } else {         res.send(html);     } }); 

Answer 2

Use fs.exists(p, [callback]) to check if the file exists before calling res.render

http://nodejs.org/docs/latest/api/fs.html#fs_fs_exists_path_callback

Node 0.6.x and older

Use path.exists(p, [callback]) to check if the file exists before calling res.render

http://nodejs.org/docs/v0.6.0/api/path.html#path.exists